Anti-Müllerian Hormone (AMH) is a protein hormone used to assess ovarian reserve, which is the remaining quantity of eggs. Many individuals using hormonal contraceptives (HC) wonder how these medications influence their AMH levels, especially when considering future fertility. The relationship between hormonal birth control and AMH often leads to confusion regarding the accuracy of testing while on the pill and what happens once it is discontinued. This article examines whether AMH levels increase after stopping hormonal birth control.
The Role of AMH in Ovarian Reserve Assessment
AMH is produced by the granulosa cells that surround the eggs within small, actively growing follicles in the ovary. The level of AMH detected in a blood test correlates strongly with the number of these small follicles, providing an estimate of the total remaining egg supply, or ovarian reserve. AMH levels remain relatively stable throughout the menstrual cycle, making it a convenient and reliable marker for assessing egg quantity.
This hormone measures quantity, not the health or quality of the eggs, which is primarily determined by age. While AMH levels help predict a woman’s response to fertility treatments like in vitro fertilization (IVF), a low result indicates a smaller pool of available eggs, but does not necessarily predict infertility.
How Hormonal Birth Control Affects AMH Measurement
While taking combined hormonal contraceptives, AMH levels often appear measurably lower. Studies show that users of hormonal birth control can have AMH concentrations approximately 25% to 30% lower than non-users. This effect is not a true depletion of the ovarian reserve but a temporary alteration of the measurement.
The hormones in the pill suppress the release of Follicle-Stimulating Hormone (FSH) from the pituitary gland. This suppression reduces the body’s signal to recruit small follicles for growth. Since AMH is secreted by these developing follicles, the decreased recruitment results in lower overall AMH secretion, leading to a seemingly lower reading on the blood test.
What Happens to AMH Levels After Stopping the Pill
AMH levels generally rise back to the individual’s true biological baseline after stopping the pill. This occurs because the exogenous hormones are cleared from the body, and the natural feedback loop between the brain and ovaries is restored. Once suppression is removed, the ovary resumes its normal process of follicular recruitment, causing AMH secretion to return to its unmasked level.
The timeline for this return to baseline is relatively quick, typically occurring within one to three months after discontinuation. Research tracking women who stopped long-term use of combined oral contraceptives (COCs) observed a significant increase in AMH levels, with one study showing an average increase of 53%. The markers returned to a normalized, stable state within eight to twelve weeks of stopping the medication.
Factors That Truly Determine AMH and Fertility
While hormonal contraceptives cause a temporary measurement shift, the most significant factor determining a woman’s AMH level and fertility remains her age. AMH levels naturally decline over time because the egg supply is fixed from birth and slowly diminishes across the reproductive lifespan. Genetic factors also play a substantial part in how rapidly this decline occurs and when a woman might enter menopause. Beyond age and genetics, certain conditions and lifestyle factors can lead to a more permanent reduction in AMH.
Permanent Factors Affecting AMH
These factors include:
- Ovarian surgery, which can physically remove or damage follicles.
- Exposure to gonadotoxic treatments like chemotherapy or radiation.
- Smoking, which negatively impacts the egg supply.
- Severe Vitamin D deficiency.
- Conditions like endometriosis.